1. Field of the Invention
The present invention relates generally to the field of surgical instruments and more particularly, to the field of forceps or tweezers for removing a parasite such as a tick from a host animal.
2. Description of the Prior Art
In recent years, there has been an alarming increase in the incidence and geographical range of tick-born disease. Both humans and animals are affected by a number of infectious agents carried in and transmitted by ticks, such as Rocky Mountain Spotted Fever and Lyme disease.
When a tick attaches to a host which may be a human or an animal, it not only inserts a portion of its mouthparts into the host to reach the blood supply, it also secretes an adherent cement onto the skin of the host which helps prevent the tick from becoming detached from the host. After the tick attaches to the host, infectious agents within the tick may be transmitted to the host by the tick during its feeding cycle. However, several hours may elapse after attachment before infectious agents are transmitted and consequently, the sooner the tick is removed, the lower the risk of infectious agents being transmitted to the host. Therefore, the best method of protecting the host from any diseases carried by the tick is a rapid, effective, and complete removal of the tick from the host.
One prior art method for removing ticks from the host is through the use of chemical agents such as petroleum jelly, fingernail polish and alcohol. In theory, the chemical agent should either kill the tick or cause the tick to release itself from the host. However, in practice, chemical agents have simply not proven to be effective. See, for example, Glen R. Needham, in "Evaluation of Five Popular Methods for Tick Removal", PEDIATRICS, Vol. 75, No. 6 (June, 1985). First, they simply do not cause the tick to remove itself from the host reliably, nor do they quickly kill the tick. In fact, a potential problem with chemical agents is that the chemical agent may irritate the tick and thereby stimulate it to transmit infectious agents to the host. Another problem is that chemical agents which do stimulate the tick to detach from the host will not also reliably remove the adherent cement excreted by the tick. It usually remains on the skin of the host after the tick detaches. The adherent cement may carry infectious agents itself or it may leave a wound in the skin of the host. In either case, the risk of infection is increased. Of course, another major drawback of chemical agents is that they must be available for use within hours after the tick attaches. It is often not possible to bring a person or animal to a supply of the chemical agent quickly enough. Alternatively, it is unlikely that people involved in outdoor recreation will carry a supply of a tick removal agent with them at all times.
Therefore, ideally, the best method to prevent transmission of disease from the tick to the host is complete removal of the tick and the adherent cement by mechanical means. However, a problem inherent in mechanical systems is that care must be exercised to avoid squeezing or crushing the body of the tick during removal because saliva, hemolymph, or gut contents which contain infectious agents can be regurgitated into the human or animal host.
Another important consideration when mechanically removing the tick from the host is to prevent accidental contact with infected tick body fluids. Infectious agents can enter a break in the skin of either the host or the person removing the tick. Consequently, direct contact with the tick should be avoided.
In order to effect mechanical removal of the tick from the host, a number of prior art forceps or tweezers have been developed. One problem with forceps of the prior art is that they rely on pressure against the body of the tick in order to obtain an adequate purchase for removal. In other words, they clamp the body of the tick like a pair of pliers. Any squeezing of the body of the tick may cause the infected bodily fluids of the tick to be expelled to the host. Another problem with the prior art tick removal forceps is that the tips are designed to clamp solidly together in continuous full surface contact. This makes removal of ticks in hair bearing areas or in folds or creases of the host's skin difficult because the host's skin may be pinched or the host's hair may be pulled. Discomfort to the host makes removal of the tick more traumatic, particularly if the host is a child or an animal.
An example of the prior art tick removing forceps is taught in U.S. Pat. No. 4,213,460. The forceps has a large handle that is attached to two closeable arms with a spoon-like structure mounted on the end of each arm. When the two arms are squeezed together, the spoon-like structure encloses and surrounds the tick. The large handle contains either a battery for supplying current to a heating element located in the spoon-like structure, or a supply of a chemical agent that would be released into the spoon-like structure in order to cause the tick to release its bite. Release of the tick depends on application of a noxious or irritating stimulus to induce withdrawal. As noted earlier, in practice, the use of chemical agents has not proven effective. Furthermore, as noted in the aforementioned Needham article "Evaluation of Five Popular Methods for Tick Removal", applying heat to a tick proved ineffective in inducing the tick to withdraw. A final disadvantage of this tick removal forceps is that it is large, bulky, and would be expensive to manufacture.
Another example of the prior art tick removal apparatus is taught in French Patent No. 2,483,770. The tip of this instrument has a ribbed surface on each of the two inner faces for pressing against and gripping the body of the tick in order to obtain an adequate purchase for removal. This instrument has several disadvantages. First, it actually squeezes the body of the tick in order to grasp it, which may cause the body of the tick to break thus releasing infectious fluids onto the skin of the host. Second, squeezing the tick may only pump fluids from the tick directly into the host through the feeding wound.
A final example of the prior art tick removal apparatus is taught in U.S. Pat. No. 4,442,837. This device has two closeable arms which can be locked in their closed position to grip the tick. This device suffers from the disadvantages of other prior art apparatus in that it relies on tight, physical grasping of the body of the tick in order to be able to remove it.
It is therefore an object of the present invention to provide a parasite removal forceps capable of grasping engorged and unengorged parasites, such as ticks, to effect their removal from the host without causing the parasite to expel infected fluids into the host.
Another object of the present invention is to provide a parasite removal forceps that atraumatically encases the parasite to allow additional purchase during removal from the host.
Another object of the present invention is to provide a simple, inexpensive, and effective apparatus for removing parasites from a host while affording maximum protection from disease to both the host and the person removing the parasite.
Another object of the present invention is to provide a forceps for removing parasites that is easy to use, even by one not skilled in the medical arts.
Another object of the present invention is to provide forceps for removing parsites that can accomodate a variety of types of parsites and a variety of sizes of each type of parasite.
Another object of the present invention is to provide a forceps for removing parasites that can be manufactured out of sterilizable materials, such as stainless steel or metal alloy.
Yet another object of the present invention is to provide a forceps for removing parasites that can be manufactured at low cost including molding the forceps from a plastic material.